EV Mode - Useless

Shouldn't have to. If the car is warmed up it will stay in EV by itself. I've even had my '04 running in auto-EV with 2 purple/pink bars in similar circumstances. It's choice, not mine. In general, for those bumper to bumper, foot barely on the accelerator things, let the car do it. I use EV on a road that has 5 stop signs in 200 yards. Rather than have the ICE light up leaving each stop, I engage EV as I slow to the first one then disengage before leaving the last one.

Because you may be dragging the battery down today to use MORE gas the next morning. Depends on the terrain and distance. If you can enter with 6 bars and get to your house with 5-6 bars, probably OK. If you get home with 3 bars, you have cost yourself in the long run. It will quickly drop to 2 when you start out in the morning and run the cold engine both to drive the car and charge the battery.

I sometimes use it for the 1/4 mile into my neighborhood but the first half is nearly flat and the last half is a pretty steep downhill, foot on the brake. Definitely never intentionally use it to leave the neighborhood though I have had it in EV (waiting for my wife to leave since she doesn't want to be behind me with my gas saving ways and she is perennially leaving late) and forgotten. The electric motor has more than enough power to climb the hill, but that is not a good way to use the battery! Just because you CAN doesn't mean you SHOULD

 

The EV threshold is...
10mph: before completed warming up
25mph: after warming up

Ken@Japan

 

Hi Ken,

Is this 25 mph limit of yours the same as on the 2G?

I'm asking because at the European 2G model we have a displayed 50 km/h limit. That should translate probably to around 48 km/h real.

Toyota Europe tells me the 3G has the exact same EV speed limit as the 2G.

So now I'm wondering if they are wrong of if the USA and Japan have different EV speed limits.

What's your take on this?

 

Ah, okay, cool. What's the "warmed up" engine-temp threshold?
.
_H*

 

I feel embarrassed to confess I had never noticed there were two distinct thresholds!

I'll leave my engine block pre-heater off this night and test it in the morning.

It's too bad the 3G was not released yet here in Portugal. I have one more month ahead of me before I can get my hands into one for testing...

 

I hate replying to myself, but I was sitting in front of the TV and remembered an error I made... back to the PC and I noticed yet another error... so here they go:

1) What do you guys mean by EV speed limit BEFORE completed warm up?

On my European 2G if the warm-up sequence starts I can not interrupt it. I have about 7 seconds time after boot up to press the EV button. After that it refuses EV mode till initial warm up is done.

So, imagining yours is the same, I can only assume you mean before the engine coolant reaches the 82-84ºC threshold. Is that it? I'm assuming the engine coolant threshold is the same worldwide. I don't have a scanner to check it unfortunately.

I am almost ready to swear it is the exact same speed, i.e. displayed 50 km/h... I would go out right now to test it, but the car is probably not stopped for a long enough period, it is still warm. I'll test it tomorrow morning and get back to you guys.

2) Hobbit, I'm sorry I only realized you were asking about the temperature threshold, not speed limit, right now when at the keyboard.

See you tomorrow.

 

2G:single threshold
JP:55km/h(34mph)
NA(DIY):55km/h(34mph)
EU:45km/h(28mph)

3G:dual threshold
JP:32km/h(20mph) and 55km/h(34mph)
NA:16km/h(10mph) and 40km/h(25mph)
EU:unknown yet

We have not got a good coolant temp meter, so the temp threshold is not known yet.

Ken@Japan

 

I read that the 3G can activate EV mode by a special start up sequence. When all operating conditions are satisfied, push and hold the EV drive mode switch
and then push the power switch while depressing the brake pedal (The engine may start depending on the system conditions).

Can someone verify this?

 

Ken, you're better than any Wikipidia, thanks!

OK, so I tried this on my way to work today:

1) European Prius 2G at garage temperature (~24ºC) overnight;
2) No engine block heater used today;
3) Start Prius, press EV button within 7 seconds, EV engaged fine;
4) Start rolling with mild acceleration, EV was sustained fine;
5) When reaching 50 km/h (display speed) EV was canceled.

This is the absolute normal behavior, and confirms what Ken had just said: The Prius 2G only has 1 threshold for EV speed limit. The maximum I could go was display 49 km/h in EV mode, at 50 km/h display it canceled it.

I was under the impression that coolant temperature was easily obtained from the CAN bus, is it not? Or is it that the codes were changed for the 3G and now you still don't know where to read it from?

 

Thank you for your comments.
Our 55km/h is real speed and we see 6km/h display offset, therefore we see at 61km/h display when the EV mode canceled.

The CAN bus messages are different between Gen2 and Gen3.
Also, we have not accessed the coolant temp sensor yet.

Ken@Japan

 

I thought it was 157F, same as the GenII. At least my ScanGage seems to confirm this.

Wayne

 

Engine coolant temp is a GENERIC OBD-II parameter, any scantool
should be able to read it.
.
I wouldn't be surprised if it's the same type of thermistor
sensor with a 5V bias, too...
.
_H*

 

I can definitely vouch for that as well.

MSantos

 

It can be practical if you find yourself in certain situations. I don't have the patience to fiddle around with it when I'm in my driveway or in the parking lot, but when freeway traffic slows to a crawl, then yeah I might use it.

 

Does anyone know why the 3G thresholds in JP and NA are different? Is there any way to reprogram a NA 3G to the JP thresholds?

 

unfortunately, the Japanese JOBD is not compatible with the OBD-II protocol, and we are spending hard time to access the temp sensor line because of the ECM water-proof connector.

Ken@Japan

 

I don't know for sure, but I'd bet on battery warranty costs.

All of these markets have different battery warranty periods, and the greater the warranty, the lower the EV speed... or so it seems...

 

I may be wrong but I think you are actually preventing your engine from getting warm before you ask some real power from it. Hence, when you use it to accelerate and merge into traffic, it is still innefficient. Letting it warm up before you reach that point would probably give you better MPG.

 

Deleted. Was already answered.

 

Driving in EV mode is like driving a Golf kart, pretty useless.